Adjustable scaffold.



L. L. ROBERTSON. ADJUSTABLE SGAPFOLD.

APPLICATION FILED JUNE 10, 1914. 1 1 1 5,975. Patented Nov. 3, 1914.

2 SHEETS-SHEET 1.

J 7/ 62X). 77 u 213 ,0 74 Q0 Z3 49 gwve/vvto'c m 79 LL. EJ675072 5/ W/Ma (Q THE NORRIS PETERS C0,. PHOTO LITHO WASHINCYON, n C.

L. L. ROBERTSON. ADJUSTABLE SOAFFOLD. APPLICATION FILED JUNE 10, 1914.

Patented Nov. 3, 1914.

- 2 SHEETS-$113111 2.

wuwwboz .L. 2205675072 UJ/I (110F061 tug/ THE NORRIS PETERS 60-.FHOTD-LITHIL, WASHINGTON, D. I

it LEVI L. nonnR'rsoN, or Mhmson, M INnEsoTA;

Specification oi Letters Patent.

immerses sciirrotii.

Patent ed NOV. 3, 1914.

A les-a1; filed June 10; 1514? serial realism ToaZZ whom it may concernBe it known that I, LEVI Ll Roiainrrson, a citizen of the United States,residing at Madison, in the county of Lac qui Pai'l e and State ofMinnesota, have invented certain new and useful Improvements ins id:-justable Scafiolds, of which thefollowing is a specification. j H

-Myj invention relates to improvements in scaffolds wherein anflapproimately, as. zontal memberis provide'd, which is lo'ng'i tudinallyextensible and I vertically adjustable with respect to uprights orsupports included therein.

to provide apparatus of the above character, which is simple inconstruction, inexpensive to manufacture, and convenient in use. 1 y

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings forming a part of this specification and inwhich like numerals are employed to designate like parts throughout thesame, Figure 1. is a side elevation of my scafiold showing thehorizontal supporting member in the uppermost position, Fig. 2 is asimilar view showing the horizontal supporting member in a lowerposition, Fig. 3 is a horizontal sectional view taken 011 line 3-3 ofFig. 2, Fig. 4 is a transverse vertical sectional view taken on line Hof Fig. 2, and, Fig. 5 is a transverse section taken on line 5'-5 ofFig; 1.

In the drawings, wherein for the purpose of illustration is shown avpreferred embodiment of my invention, the numeral 10 designates uprightsor upstanding supports, preferably in the form of ladders. Thesesupports or ladders are identical whereby a detailed description of onewill suffice for both. Each support or ladder 10 comprises spacedstandards 11, which are Vertically inclined when the scafiold is in use,as shown. The standards 11 are connected by spaced rungs 12, asiscustomary. Formed upon the inner sides of the standards 11 adjacent theinner edges thereof are longitudinal recesses 13, within which areadapted to slide links 14:. Each link c0m-- prises bars or members 14:,which are ar ranged in transversely alined pairs and rigidly connectedby suitably spaced rods 15 or the like, forming a surface upon which Animportant object of the invention is the joperatoifmay walk. Theendsofwthe adjacent bars 1 1 have'knee joint pivotal connections as shown at16, which allows the links to be swung upwardly with respect tothesupportswor ladders 10 but positively preventing them from beingswung downb'eyojnd'a horizontal position.

above st'ated, the links let a e adapted to slide within'thel'on'gitudinalrecess 13,

removable transverse rods 17 detachably connected withthe standards 11and arranged inwardly of the links, as shown. The rods '17 are arrangedin, spaced superposedrelation, whereby each rod in addition topreventing the downward movement of t hefl inksserves. as a support forthe outermost horizontally arranged link, where; by thehorizontallyarranged links may be vertically adjusted by removing or replacing therods 17. The scaffold may be 1011- gitudinallyexpanded or contracted,while the horizontal links remain in the same "horizontal plane, byremoving or inserting certain of the outer links from or into therecesses 13, as is obvious. The supports or ladders 10 may be foldedfiat upon each and the same are held therein by means of other, thelinks 1d passing entirely within the recess 13, as is obvious.

The links 14 are provided with transverse openings 18, (see Fig.5)adapted to receive the hooked ends 18 of diagonal brace rods 19 and 20.The hooked ends 18 are preferably provided with transverse openings, ,toreceive cotter pins 19or the like, as shown in Fig. 5. The opposite endsof the brace rods 19 and 20 are hooked to engage with eyes 20, securedto the standards, as shown. The brace rods 20 are preferably providedwith turn buckles 23,

whereby they may be extended or contracted.

The operation of the apparatus is as fol lows :When it is desired toelevate the horizontal supporting member formed of the links 14, theupper rods 17 being removed, such supporting member is moved toward theupper ends of the standards 11, the links sliding in the grooves 13, asis obvious. Subsequently to this the upper rods 17 are secured tothestandards by being passed through the openings therein, the uppermostrods serving to support the hori'zontalmemher. The diagonal braces 19and 20 are now secured to the standards and horizontal member, forholding these parts in the proper position. The horizontal member may belowered to assume the position shown in Fig. 1, as is obvious. It isalso obvious that the entire apparatus may be collapsed to lie fiat, forthe purpose of ship ment or storage.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same, and thatvarious changes in the shape,

size, and arrangement of parts may be resorted to Without departing fromthe spirit of the invention or the scope of the subjoined claims.

Having described my invention,I claim 1. In a scaffold, a plurality ofspaced upstanding supports, and a member extending between the supportsformed of a plurality of pivoted elements with the opposite end elementsextending longitudinally of 8. In a scaffold, a plurality'of spacedupstanding supports having longitudinally extending guide means, and aflexible member connecting the upstanding support and formed of aplurality of links adapted for longitudinal movement within the guidemeans.

4. In a scaffold, a plurality of spaced upstanding supports havinglongitudinally extending grooves provided with open'sides, a flexiblemember connecting the upstanding supports and formed of a plurality oflinks having knee joint pivotal connection and adapted for longitudinalmovement within the grooves, and removable rods connected with thesupports adjacent the longitudinal grooves to retain the links therein.

5. In a scaffold, a plurality of spaced u standing supports, and anapproximate y horizontal supporting member extending between thesupports and embodying a plurality of relatively movable elements andhaving the end elements longitudinally adjustably mounted upon thesupports.

In testimony whereof I aifix my signature in presence of two witnesses.

LEVI L. ROBERTSON. Witnesses:

L M. HEGRE, OBERT R. NELSON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

- l Washington, D. G.

